Free tools
Calcunia health calculators provide numerical landmarks for weight, energy needs, exercise, sleep, hydration and alcohol estimates. They are not diagnostic tools; they organise data many people already track, such as height, weight, age, sex, activity level, heart rate or rest time. BMI, BMR, calories burned, water needs, protein intake, sleep cycles and blood alcohol concentration each require a different interpretation. A body index, a workout estimate and an alcohol reading do not carry the same uncertainty or the same consequences.
BMI relates weight to height, yet it says nothing about muscle mass, fat distribution or athletic build. Weight-related calculators should be treated as screening references rather than full descriptions of health status.
Basal metabolic rate estimates resting expenditure before activity is added. Calorie deficit, macro and workout calculators connect food intake, movement and progress, but they work best when trends are followed over time.
Sleep-cycle tools use approximate intervals. Falling asleep, waking during the night and personal rhythm affect the result, so a planned bedtime should include the time needed to actually drift off.
Water and protein needs change with body weight, heat, sport and nutrition goals. The calculators give a practical starting point when current intake is clearly too low or unusually high.
Blood alcohol concentration is sensitive to food, sex, body mass, drink strength and elapsed time. An online estimate must never be used as permission to drive or ignore safety rules.
BMI uses only height and weight. A muscular athlete can receive a high score even when body fat and health risk are very different from someone with the same weight and less muscle.
They are approximate because pace, terrain, body mass, running economy and intensity all change energy use. The value is more useful for comparing similar sessions than for exact nutrition accounting.
No. Alcohol absorption and elimination vary too much between people. A recognised test device and local law are the only safe references for driving decisions.
Calculate BMI, identify the adult category and complete the reading with healthy weight range, waist measurement, activity and indicator limits.
Estimate resting energy needs, compare activity levels and turn this benchmark into maintenance, weight-loss or lean-gain targets.
Calculate daily calories by age, height, weight, sex, activity and goal. Estimate BMR, TDEE, maintenance, weight loss, lean gain and macronutrients.
Calculate your estimated due date from the last period, conception or ultrasound. Follow pregnancy weeks, trimester, remaining days and key milestones.
Estimate a reference weight range from height, profile, morphology and goal. Compare Lorentz, Devine, Creff and the healthy BMI range without reducing the result to a single number.
Estimate body fat percentage with US Navy, Deurenberg and BMI-based methods. Compare fat mass, lean mass, category, target zone and trend.
Calculate daily water needs by weight, age, activity, climate and exercise. Estimate liters per day, glasses, bottles, hourly plan and hydration tips.
Calculate protein needs by weight, activity and goal. Estimate grams per day, g/kg, protein per meal, optimal range and food equivalents.
Calculate target heart rate from age, resting HR, intensity and the Karvonen method. Get cardio zones, bpm, max HR, reserve HR and training tips.
Calculate calories burned by activity, weight, duration and intensity. Estimate kcal, MET, calories per minute, weekly projection, cardio zones and activity comparison.
Calculate macronutrients by calories, weight, activity and goal. Estimate protein, carbs, fat, grams per meal, ratios, scenarios and food equivalents.
Estimate maintenance calories, daily deficit, target intake, macronutrients and a weekly weight-loss projection.
Place pregnancy weight gain in context by pre-pregnancy BMI, week, trimester and pregnancy type with a cautious reading.
Estimate ovulation date, fertile window, most favorable days, next period and key cycle phases with cautious interpretation.
Calculate an ideal bedtime or wake-up time from complete cycles, sleep latency, sleep duration and recovery goal.
Calculate waist-to-hip ratio, compare ranges, understand your result and learn how to measure waist and hips correctly.
Calculate calories burned while running from distance, duration, pace, body weight, terrain and intensity with charts, zones and advice.
Calculate calories burned while cycling from duration, distance, speed, body weight, bike type, terrain and intensity with charts, zones and advice.
Estimate blood alcohol level cautiously from drinks, drinking duration, body weight and profile with clear safety reminders.
Set a realistic daily step goal from your current average, available walking time and sustainable weekly progression.